.middle{
    width: 1200px;
    height: 600px;
    margin: 50px auto;
    border: 1px solid red;
}
.callus{
    height: 40px;
    border-bottom: 1px solid red;
    font-family: 仿宋;
    line-height: 40px;
    font-size: 25px;
    padding: 15px;
}